There are many different types of guitars and guitarist out there. While we may take different paths on our guitar playing journey, we will all inevitably have to change our strings. The question is when, why and which ones?
If you cannot remember the last time you have changed your strings then the answer is NOW.. The need for new strings can be different from player to player, dependent mostly on the amount of playing time the instrument is getting. Average "home guitarists" and younger students should be changing strings every three months or so. While length of time can be a good way to determine when to change strings, age is not the only determining factor for string changing.
Every pack of stings is different and may have a different length of life depending on what they are put through. The number one thing to watch out for is string corrosion. Over time the strings will become discolored and dingy looking. Corrosion will build up on the strings. Wiping the strings clean after use can slow this process. Be sure to wipe the underneath side of the strings as well.
String corrosion is bad for multiple reasons. Corroded guitar strings don't sound as good as new strings. More importantly corroded strings can expedite fret wear. Fret ware is when the strings start to create indentations on the metal frets. Fret wear can cause buzzing sounds and intonation problems. While fret wear over time is unavoidable you can certainly slow it down the process by keeping clean strings on your guitar.
Picking the right strings for you...
First be sure to select the appropriate type of strings for your instrument. For example, nylon strings for classical guitars, acoustic strings for acoustic guitars, and electric strings for electric guitars. From there is becomes a situation of player preference. If you are a newer player or lack finger strength you may try lighter gauge strings. Look at the gauge of the "High E" string, the higher the number the harder the tension. Heavier tension strings have better tone and lighter strings have better playability. Strings are also made of different materials and some are coated with a protective finish to increase lifetime. The best thing to do is grab some strings and figure out what you like.
One last tip..... grab two sets if it is your first time changing strings.........Good luck!